Lock



E; N. .JACOBI Oct. 26, 1937.

LOCK

File d Nov. 18, 1955 2 sheets-sheet" 1 Patented Oct. 26, 1937 UNITED STATES PATENT oFFicE LOCK Application November 18, 1935, Serial No. 50,324

12 Claims.

This invention relates to improvements in looks and refers particularly to key controlled cylinder locks.

It is an object of this invention to provide an 5 improved and simplified manner of providing armoring or protection for looks of the character described.

Morespecifically, it is an object of this invention to provide an armor cap for cylinder locks of lo simplified and inexpensive construction, and a novel manner of holding the same assembled with the lock structure.

Another object of this invention is to provide an armor cap for cylinder looks so mounted as to be 15 rotatable with the cylinder and held in position by a freely rotatable connection with the lock casing so constructed that in an intermediate position of rotation, the connection is engageable and disengageable to facilitate assembly of the ,20 parts.

\ With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially 35 as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

30 The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

35 Figure l is a view partly in longitudinal section and partly in side elevation of a lock embodying this invention;

Figure 2 is a sectional view taken through Figurel. on the plane of the line 2-2 40 Figure 3 is a cross sectional view taken through Figure l on the plane of the line 33;

Figure 4 is a perspective view of the armor cap per se shown detached from the lock and viewed from the inside thereof;

45 Figure 5 is a perspective view. of the front end portion of the lock casing; and I .Figure' '6 is. a perspective View of the front .en portion of the lock cylinder.

Referring now more particularly to the accom- .,5 panying drawings in whichlike numerals indicate -.like parts throughout the several .views, .the numeral designates a lock casing mounted in .the present instance inatubular housing fi. The

.zcasingasti has a bore-1,1 torotatably receive a lock ,5 5 -cylindem8 which held against endwise displacement by stop means, indicated generally by the numeral 9. Suitable stop means (not shown) are also provided to limit the turning movement of the cylinder 8 to a predetermined number of degrees to and from the locked position shown 5 in the drawings.

The lock illustrated is of the pin tumbler type in which the casing 5 has a plurality of locking plungers Ii! mounted radially therein and yieldingly projected by springs H toward thecylinder 1o 8. With the cylinder in its locked position of rotation, .as shown, theseplungers l0 align with pin tumblers l2 slidably mounted in radial apertures in the lock cylinder.

As long as no key is present'in the keyway J3 of the cylinder, the plungers Ill project into the cylinder and secure the same against rotation. Upon insertion of a proper key M into thekeyway I3, the pin tumblers l2 are all moved outwardly of the cylinder a distance sufficient to align the 0 engaging ends of the pin tumblers and the plungers H) with the periphery of the cylinder to free the cylinder forrotation.

Inasmuch as the pin tumblers l2 engage the wallofthe bore I as soon as the cylinder is turned from its locked position, it follows that upon rotation of the cylinder. away from its locked position, the key It isheld against withdrawal.

Covering the-front of the cylinder and casing is anarmor cap 15. This cap isstamped from sheet metal and hardened to resist attacks of chisels and drills. On its outer periphery, the cap has an inwardly directed cylindrical flange It, the outer diameter of which is substantially equal to that of the casing .5 to fit in the bore of .the housing 6, as shown, and project rearwardlyover a reduced neck ll on the front of the casing.

The central portion of the cap is pressed in- ,wardly to form a substantially rectangular projection I8 on its inner or rear face, the rear extrem- 4p ity of which fits into a correspondingly shaped transverse slot 19 across the front end ofthe .cylinder so that when properly assembled, the

cap is non-rotatably joined to the cylinder.

The inwardly fiared depression 20 resulting a from the formation of the rearward projection 18 serves to guide the key into the key slot 21 through the cap which aligns with the keyway l3 of the cylinder, and as best shown in Figure 1,

When the cap is in position and a key is inserted,

23 on the flange it which are freely rotatably engaged in a groove 24 formed in the neck I! of the casing. The groove 24 is defined by the shoulder 25 which joins the neck II with the major diameter of the casing and an outwardly directed ledge or flange 26 on the extreme front end or the neck i1.

This ledge or flange 26 is interrupted at two diametrically opposite portions to permit the passage of the lugs 23 when the cap is in its position of rotation aligning its lugs with the interruptions. bly and disassembly of the cap with the casing is possible in only two positions of rotation of the cap with respect to the casing, and inasmuch as the cap must be non-rotatably engaged with the cylinder to permit the same to be moved endwise into operative engagement with the easing, it follows that the assembly and disassembly of the cap with the lock also requires the cylinder to be in a predetermined position of rotation.

This position of rotation lies midway in the range of turning movement of the cylinder. Being so disposed, there is no positive securement of the cap in this one position of rotation, but displacement of the cap during manipulation of the lock is prevented by the shoulder 22 on the key I4 engaging the outer face of the cap adjacent its key slot 2|. Obviously, during normal operation of the lock, the cap and cylinder are seldom, if ever, stopped at the one point at which the cap is removable and inasmuch as actual removal of the cap is precluded by the presence of the key, the lack of a positive retaining means for the cap during this slight interval is not detrimental.

On the other hand, as will be readily apparent to those skilled in the art to which this invention appertains, this manner of securing the cap in place permits of the utmost simplicity in design and construction, and also insures low cost as it permits the cap to be formed entirely as a stamping.

To guard against the possibility of having the corners of the lugs 23 strike the corners of the interruptions in the retaining ledge on the front end of the casing, the corners of the ledge are chamfered at 26, as shown in Figure 5. In view of the fact that the cap can only be assembled with the casing and cylinder when the cylinder is in one position of rotation and inasmuch as the key cannot be inserted or withdrawn in this position of rotation, the assembly of the cap onto the lock must follow one of two methods.

A special key, not shown, may be used. Such key is like the regular key except that it has no regular head, but is slabbed off so that its projecting portion may pass freely through the key hole in the cap. This key is then used to turn the cylinder to the required position of rotation whereupon the cap may be slipped over the projecting end of the special key to its proper assembled position.

The other manner of assembling the cap with the lock is to apply the cap before the tumblers of the lock are inserted. When this method is practiced the cylinder not being restrained against rotation by the presence of tumblers, may be freely turned to its position at which the cap can be applied and then after they cylinder and cap are turned back to the locked position of rotation, pin tumblers and locking plungers may be assembled with the cylinder and casing.

What I claim as my invention is:

Hence, it will be seen that assem- 1. In a look, a bored casing, a lock cylinder rotatable therein through a predetermined number of degrees upon the insertion of a proper key into the cylinder, an armor cap covering the front end of the cylinder, and means including a bayonet joint and a shoulder on the key in the cylinder for retaining the cap assembled with the cylinder.

2. In a look, a bored casing, a lock cylinder rotatable therein through a predetermined number of degrees upon the insertion of a proper key into the cylinder, said lock being so constructed that withdrawal of the key is impossible when the cylinder is in an intermediate position of rotation, an armor cap covering the front end of the cylinder, and means for positively holding the cap assembled with the cylinder except in one predetermined intermediate position of rotation of the cylinder at which point the cap is held against displacement from the cylinder by the presence of the key used to turn the cylinder.

3. In a lock, a bored casing, a lock cylinder rotatable in the casing upon the insertion of a proper key therein, an armor cap covering the front end of the cylinder, and interengaging means on the casing and cap for positively retaining the cap in place except when the cap is in one position of rotation with respect to the casing in which position said interengaging means is readily engageable and disengageable, and said cap being so associated with the cylinder as to be held against displacement when in said predetermined position of rotation by a key in the cylinder.

4. In a look, a bored casing, a cylinder rotatable in the casing upon the insertion of a proper key, an armor cap covering the front end of the cylinder and non-rotatably joined thereto so as to turn with the cylinder, inter-engaging means on the casing and the cap to positively retain the cap in place except when the cap is in one position of rotation with respect to the casing, and means on said cap so positioned as to be engaged by a part on the key used to turn the cylinder and cap whereby the key holds the cap against displacement when in said predetermined position of rotation with respect to the casing.

5. In a look, a bored casing, a cylinder rotatable therein upon the insertion of a proper key, an armor cap covering the front end of the cylinder and non-rotatably joined thereto so as to turn with the cylinder, a tongue and groove connection between the casing and the cap for positively holding the cap'in place except when the cap is in one predetermined position of rotation with respect to the casing at which said tongue and groove connection may be made and broken, and means on the cap engageable by a key used to turn the cylinder so that such key holds the cap against displacement when the cap is in said predetermined position of rotation withrespect to the casing.

6. In a look, a bored casing, a lock cylinder rotatable therein upon the insertion of a proper key, an armor cap covering the'front end of the cylinder and the casing, inwardly directed radial lugs on the cap engaging in an annular groove in the casing for positively holding the cap inplace except in one relative position of the cap and casing in which position said lugs align with gateways leading to said annular groove, said cap being rotatable with the cylinder at all times and said gateways being so positioned that said predetermined relative position of rotation at which the lugs on the cap align with the gateways is disposed medially in the range of rotation of the cylinder and cap relatively to the casing.

7. In a look, a bored casing a reduced neck on the front end of the casing, an outwardly directed flange on said neck coacting with the shoulder formed at the juncture of the neck with the main body of the casing to define an annular groove, said flange having interruptions providing gateways to the groove, a cylinder rotatable in the casing bore upon the insertion of a proper key into the cylinder, an armor cap covering the front end of the cylinder and the neck on the casing, said cap being non-rotatably joined to the cylinder so as to turn therewith, and inwardly directed radial lugs on the cap engageable in the annular groove on the neck of the casing to positively hold the cap in place except in one position of rotation at which the lugs align with the gateways leading to the groove, and said cap having a part engageable by a shoulder on the key used to turn the cylinder which acts to hold the cap against displacement when in said predetermined position of rotation.

8. In a look, a bored casing having an annular groove in its peripheral surface, a lock cylinder rotatable therein upon the insertion of a proper key, said cylinder having a non-circular recess in its front end, an armor cap covering the front end of the cylinder and casing and having a rearward non-circular projection received in the non-circular recess in the cylinder so that the cap is non-rotatably joined to the cylinder, a rearwardly directed peripheral flange on said cap fitted over the extreme front end of the casing, and inwardly directed radial lugs on said peripheral flange engaging in said annular groove in the casing to normally hold the cap in place.

9. In a look, a bored casing having an annular groove in its peripheral surface, a lock cylinder rotatable therein upon the insertion of a proper key, said cylinder having a non-circular recess in its front end, an armor cap covering the front end of the cylinder and casing and having a rearward non-circular projection received in the non-circular recess in the cylinder so that the cap is non-rotatably joined to the cylinder, at rearwardly directed peripheral flange on said cap 50 fitted over the extreme front end of the casing,

and inwardly directed radial lugs on said peripheral flange engaging in said annular groove in the casing to positively hold the cap in place except in a predetermined position of rotation sub- 55 stantially midway in the range of rotation of the cylinder and cap, and said cap having a part engageable by a shoulder on the key used to turn the cylinder whereby the cap is held against displacement by the key in passing said predeter- 50 mined position of rotation.

10. In a look, a bored casing having an annular groove in its peripheral surface, a lock cylinder rotatable therein upon the insertion of a proper key, an armor cap covering the front 65 end of the cylinder and casing, means for holding said cap and cylinder against relative rotation so that the cap must turn with the cylinder at all times, a rearwardly directed peripheral flange on the cap fitted over the extreme front end of the casing, inwardly directed radial lugs on said flange to engage in the annular groove of the casing and normally holding the cap in place, and the peripheral portion of the casing forward- 1y of its annular groove having gateways leading from the groove to the front end of the casing to permit the assembly of the cap onto the casing and cylinder, said gateways being so located with respect to the range of rotation of the cylinder that assembly of the cap on the casing and cylinder is possible only When the cylinder is turned to a predetermined intermediate position.

11. In a look, a bored casing having an annular groove in its peripheral surface, a lock cylinder mounted therein, tumblers holding the cylinder against rotation in the casing except upon insertion of a proper key into the cylinder, the cylinder having a non-circular recess in its front end, an armor cap covering the front end of the cylinder and casing and having a rearward noncircular projection received in the non-circular recess of the cylinder so that the cap must turn with the cylinder at all times, said cap having a key hole, inwardly directed radial lugs carried by the cap to engage in said annular groove in the casing, the casing having gateways in its peripheral surface forwardly of its annular groove leading from the groove to the front end of the casing to allow passage of the radial lugs on the cap and enable assembly of the cap onto the casing and cylinder, said gateways being so located as to require rotation of the cylinder to a predetermined position at which its non-circular recess is correctly related to the gateways so that assembly of the cap onto the lock requires the use of a special key the projecting portion of which may pass through the key hole in the cap or the application of the cap prior to insertion of the tumblers.

12. In a lock, a bored casing having a bayonet slot in its front end, a cylinder rotatable in the bore having a keyway enlarged at its mouth to provide a substantially rectangular recess at the front end of the cylinder, an armor cap stamped from sheet metal covering the front end of the cylinder and casing, said armor cap comprising a circular disc with an annular rearwardly directed flange embracing the front end of the casing and having a depressed portion around a keyhole forming a rectangular driving lug engageable in the recess at the front end of the cylinder, and a retaining lug extending radially in from said flange for engagement in the bayonet slot to secure the cap in place, said retaining lug being so positioned angularly with respect to the rectangular depressed portion and the mouth of the- 

